The present disclosure relates to an inverter, a core part of an electric vehicle, and more particularly, to enhancing the maximum torque of an induction motor and decreasing energy consumption when an inverter controls the induction motor.
The induction motor is a typical example of an alternating current (AC) motor. In response to sliding when an induced current is generated at a rotor of a conductor due to a rotating field formed by a stator, the induction motor may generate torque and operate a load. The induction motor may be roughly divided into a single-phase induction motor and a three-phase induction motor by an input AC power supply type.
Recently, the induction motor is being frequently applied to an electric vehicle. An induction motor applied to the electric vehicle may be driven through vector control. In this case, the inverter of the electric vehicle controls the torque of the induction motor through a D axis current and a Q axis current.
However, since a typical inverter fixes the D axis current and changes only the Q axis current when controlling the torque of the induction motor, it was difficult to generate the maximum torque of the induction motor.
Also, since a typical inverter fixes the D axis current and changes only the Q axis current in order to generate the same torque, there was a limitation in that current consumption is high.